Daniel Cormier's adductor tear that led to cancellation of his scheduled UFC 206 main event with Anthony "Rumble" Johnson greatly hurt the marketability of a show that from an action standpoint, looked great on paper.
In this case, the show more than lived up to what it looked to be when looking at it in advance. But the show that a lot of fans then chose to pass on -- sandwiched between a Conor McGregor-headlined show and a Ronda Rousey-headlined show, and then losing its biggest fight, ended up as one of the most exciting and even memorable events of the year.